Emma Gottung

In North America, ²/₃ to ³/₄ of the pearly mussels are endangered, threatened, extinct or in need of conservation status. Pearly mussels are key in aquatic ecosystems; they filter and clear water. Mussels are filter feeders that clean the water of microorganisms and chemicals. When mussels are not present in an environment, the water may be not as clear. Sediments potentially impact pearly mussel clearance rates, feeding, respiration and diminished health. Dams can cause water to be backed up causing an increase in silt load. Mussels in unstable sediments can sink into it. The Tioughnioga River was surveyed in 2010 and Brook Floater (Alasmidonta varicosa), Elktoe (Alasmidonta marginata), Green Floater (Lasmigona subviridis), and Yellow Lamp Mussels (Lampilis cariosa) were found. Both the green Floater and the Brook Floater are listed as NYS “Threatened.”

Over the period 2-4 August, we surveyed pearly mussels in the East Branch of the Tioughnioga River upstream and downstream of the confluence with Haights Creek and Trout Creek (42°40’25.1”N 76°04’29.0”W). The survey was to facilitate removal of a boulder, cobble, and gravel bar causing upstream flooding and involved two faculty, one graduate student, and three undergraduate students. We did not find pearly mussel species of greatest conservation need in the 550 meters downstream of the stone and gravel bar or 100 meters upstream of the stone and gravel bar. We did find spent pearly mussel shells and shell fragments of a variety of pearly mussel species, none SGCN. We found one live pearly mussel (Eastern elliptio; Elliptio complanata) in the 100 meters reach upstream of the gravel bar. It was in water approximately 1m deep. We also surveyed the 3.7 kilometers (2.3 miles) upstream of the proposed dam removal area for pearly mussel SGCN likely to be exposed to air with the water level drop occurring when the stone and gravel bar is removed. Most (approximately 97%) of the 3.7 kilometers reach has a U-shaped channel with no probable pearly mussel habitat along the edges. We examined approximately 20 sites with gradual banks and emergent plants. In none of those sites did we identify any impediment to pearly mussel movement into deeper water. Additionally, we performed quick (approximately 30 minute and 60 minute) searches in four areas in the 3.7 kilometer reach. We found two SGCN (Yellow lampmussel and Elktoe) upstream in the 3.7 kilometer reach. More clay silt and flocculent organic materials were found on the river bottom closer to the stone and gravel dam than in upstream portions of the 3.7 kilometer reach. Removal of the boulder, cobble, and gravel bar, currently causing upstream flooding, will facilitate cleansing of the clay silt and flocculent organic materials providing enhanced pearly mussel habitat quality and quantity in the 3.7 kilometer reach upstream.